Detection of environmental ultraviolet radiation by the induced electroluminescence in a ceramic detector

Environmental ultraviolet (UV) radiation can be detected passively by a ceramic sensor by measuring the radiation-induced electroluminescence (EL). The phenomenon that metal-oxide ceramic material doped with certain impurities can emit photons under high electric fields after irradiation by UV has been observed in our laboratory. This phenomenon of EL only exists after the sensor has been irradiated by UV radiation. After the emission of photons, the sensor material returns to the normal state, and no more photons win be emitted even though the electric field is applied again. The emitted light may have different wavelengths which depend on the base material of the sensor and the impurity. The peak height of the EL curve represents the number of radiation-induced photons which is directly in proportion to the exposure of the UV radiation; thus the radiation-induced EL can be used as the UV radiation detector. A device for measuring the radiation-induced EL was constructed using a high-vacuum chamber and a facility to supply a high electric held across the UV sensor. A photodetector with its output system is used to register the emitted light from the EL. The UV-induced EL in ZrO/sub 2/ with zinc oxide as impurity has been obtained. Other base materials such as Gd/sub 2/O/sub 3/ and MgO are being investigated for the same phenomena.